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What does heating helium do?

  1. Jun 25, 2012 #1
    For example, if I had contained helium, and then I increased the temperature and installed spinners and motors inside would that move due to the activity produced by the high energy helium , or would the movement caused by the helium not be powerful enough to move the spinners. (I think it should because high temperatures cause the gas molecules to move very quickly and become extremely unstable)
     
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  3. Jun 25, 2012 #2

    DaveC426913

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    Helium would act essentially like any other gas. I'm not sure what your setup is, or what these spinners and motors do.
     
  4. Jun 26, 2012 #3

    LURCH

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    What are these "spinners"?
     
  5. Jun 26, 2012 #4

    DaveC426913

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    My guess is blades - for fans or turbines. But the OP seems to have some misconceptions about what the heated helium will do.
     
  6. Jun 26, 2012 #5
    So basically I wanted to find a way to see if heating gas will generate movement and move a turbine to generate electricity, similar to how we heat water to create steam to generate electricity. I was basically wondering if the same could be done perhaps with a sensitive gas such as helium or any other for that matter.
     
  7. Jun 26, 2012 #6

    DaveC426913

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    It will take more energy to heat the gas than you will gain from the turbines. This is a "free energy" design idea. Alas, it will not work.
     
  8. Jun 26, 2012 #7
    But what if the heat is already excess and simply being wasted?
     
  9. Jun 26, 2012 #8

    mfb

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    You can power a generator with heated helium with the right setup. However, why do you plan to use helium? Air is cheaper. If burning materials might be a problem, use nitrogen.
     
  10. Jun 26, 2012 #9
    Oh ok, but what do you mean by burning materials and the use of nitrogen?
     
  11. Jun 26, 2012 #10
    Also if air is heated, is it sensitive enough to move the turbine and generate electricity? That is my main concern
     
  12. Jun 26, 2012 #11

    DaveC426913

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    That is entirely up to your setup. It is certainly possible to heat up a gas and have it turn a turbine.

    Though it would be more effective to start with liquid water and heat it to steam, which would cause it to expand many-fold.

    The expansion of a gas is directly proportional to the heating (Charles' Law). so to double the volume, you'd have to double the temperature (that's absolute temp - Kelvins). i.e. to double the volume of a room temperature gas would require heating it to about 600K (~320C).
     
  13. Jun 26, 2012 #12

    QuantumPion

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    Yes you can make an engine using helium as the working fluid. It would run on the Brayton cycle, similar to gas turbines and jet engines. Helium can and has been used for high temperature gas cooled nuclear reactors. To answer the topic title question, heating helium "does nothing", which is why it is useful for a coolant at high temperatures (i.e. it does not chemically react with materials nor does it absorb neutrons and become radioactive).
     
  14. Jun 26, 2012 #13

    sophiecentaur

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    But I imagine it is the very devil to contain in a cooling circuit.
     
  15. Jun 26, 2012 #14

    QuantumPion

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    Main generators are cooled with hydrogen and they work just fine. I'm sure there are some losses due to leakage and diffusion but not so much that can't be accounted for by make-up.
     
  16. Jun 26, 2012 #15

    sophiecentaur

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    And I guess what does get out is harmless, wherever it's been.
     
  17. Jun 27, 2012 #16
    Heating helium will make hot helium. Helium is very unreactive, so you aren't going to burn the helium or anything like that. Heating gas causes it to expand, so you can use it to turn turbines if you desire. Is there any reason to use helium here, other than water? Steam turbines have existed for some time now.
     
  18. Jun 27, 2012 #17

    DaveC426913

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    The OP has mentioned more than once his/her belief that helium is somehow sensitive or unstable when heated. It sounds like he/she is hoping that heating He will increase its buoyancy in air more than it might some other non-buoyant gas. Hopefully, he/she is realizing this is barking up the wrong turbine tree, yes?
     
  19. Jun 27, 2012 #18

    QuantumPion

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    I don't think so. At least not in this thread. The OP posted:

    I'm not exactly sure what she meant by "sensitive gas" but I took it to mean its low density and molecular weight. And she specifically mentioned "any other gas for that matter" so I'm pretty sure she is just wondering what the effect of using different fluids for a heat engine would be.
     
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